Frog lube is junk, I've had rust get WORSE on some stainless tactical folders that were carried daily, had it seize and allow minor rust a couple 1911's (the company rep said it was because the gun was cold that it siezed), and the guys running the company are shady, ripped off someone else for the formula. The only claim they make that is valid is that it is natural and non-toxic.
I have over 20 years in the modern firearms business, the only modern cleaners/lubes I use are, MFR-7, Gunzilla, MPro-7, Wislon Combat grease and oil (on 1911s and Hi-Powers), and on a VERY dirty bore, I will sometimes use Butch's Bore Shine (stuff smells like death by chemical but works.
The only one of these I use on my muzzleloaders is the Gunzilla. I did a freeze test in my freezer and it didn't turn to a block of ice (I know, not very scientific) and I use it mostly as a lock lube. If I know it will be a while before I can clean the bore after a range session, I swab the bore with it before leaving the range. I plan to do some tests using it as a patch and/or felt wad lube, at some point. Initial test shots using it on felt wads with round balls shot from a smoothie resulted in those rounds impacting higher than with my usual olive oil and beeswax lube.
For rust protection on the outside of the barrel and lock I just use beeswax.